Study on microstructure evolution and mechanical properties of high-strength low-alloy steel welds realized by flash butt welding thermomechanical simulation

Abstract Defects would occur in the weld joint of wheel rims during post-flash butt welding (FBW) process suffering from poor plasticity, which will deteriorate quality and lifecycle finish products. Therefore, FBW 440CL high-strength-low-alloy (HSLA) steel was physically simulated influence flash parameters on joints systematically evaluated this study. The results showed that width heat affected zone increased with accumulated allowance (? f ) while declined accelerated speed (v ). recrystallization level be intensified ? . Meanwhile, acceleration v populated WZ a more homogeneous microstructure, higher degree lower dislocation density. hardness slightly reduced (202 ? 195 HV) as but obviously dropped (192 177 All tensile samples were fractured at BM location properties exhibit good match those BM, slight increase strength (UTS: 468 ~ 493 MPa; YS: 370 403 MPa) mild decrease plasticity (EL: 39 44%; RA: 74 79%). Furthermore, both ductility downward tendency increment However, decreased advancement These findings valuably referential to real HSLA steels optimized microstructure mechanical performance.